1. Field of the Invention
The present invention relates to an organic porous material useful as an adsorbent, a filler for chromatography, and an ion exchanger, a process for manufacturing the organic porous material, and an organic porous ion exchanger.
2. Description of the Background Art
As a porous material having a continuous pore structure comprising interconnected macropores and mesopores in the walls of the macropores, inorganic porous materials formed from silica and the like are known (U.S. Pat. No. 5,624,875). Development of application of these inorganic porous materials as fillers for chromatography has actively been undertaken. However, since these inorganic porous materials are hydrophilic, complicated and expensive procedures such as a hydrophobicizing treatment of the surface and the like are required to use these materials as adsorbents. In addition, when retained in water for a long period of time, the inorganic porous materials release silicate ions produced by hydrolysis of silica in water. Therefore, it is impossible to use the inorganic porous materials as ion exchangers for producing deionized water and high-purity water. On the other hand, if used as fillers for chromatography, the inorganic porous materials have been reported to exhibit remarkably improved performance over conventional particulate fillers. However, since mesopores in the inorganic porous materials have a size of 50 μm at most due to the manufacturing method, there has been a restriction imposed on a process in which a material is processed at a large flow rate under a low pressure. In addition, it is common in the field of chromatography to wash fillers with a strong alkaline aqueous solution such as a 0.5 M sodium hydroxide aqueous solution. However, if the inorganic porous materials are repeatedly washed with such an aqueous solution, silicate and the like are solubilized or eluted due to hydrolysis, resulting in significant weight loss of the filler. It is thus impossible to frequently carry out the washing operation. For the same reason, an alkaline eluant cannot be used in a system using any of the inorganic porous materials as a filler, imposing a limitation to the object of measurement.
As organic porous materials having continuous pores, porous materials possessing a particle aggregation-type structure have been disclosed in F. Svec, Science, 273, 205–211(1996) and other publications. The porous materials obtained by the method described in these publications has a small pore volume and an insufficient mesopore size due to the particle aggregation-type structure. For these reasons, a limitation is imposed on application of the pore materials in a process with a large flow rate under a low pressure. In addition, since conventional organic porous materials and porous ion exchangers, made by introducing ion exchange groups into the conventional organic porous materials, have many internal structural defects, low strength, poor durability against swelling and shrinkage, and a broad pore distribution, these organic porous materials exhibit only insufficient separating performance when used as a filler for chromatography.
Therefore, development of organic porous materials having a large pore volume and high physical strength, containing pores with a large and uniform pore diameter, being free from internal structural defects such as macrovoids, and having a continuous pore structure has been strongly demanded.
The present invention has been achieved to solve the above problems in the conventional technology and has an object of providing an organic porous material useful as an adsorbent having high physical strength and excelling in adsorption capacity and adsorption rate, an ion exchanger excelling in durability against swelling and shrinkage, and a filler for chromatography exhibiting high separation capability, a process of manufacturing the organic porous material, and an organic porous ion exchanger.